/*
 * Zmanim Java API
 * Copyright (C) 2004-2008 Eliyahu Hershfeld
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
 * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if
 * not, write to the Free Software Foundation, Inc. 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA or connect to: http://www.fsf.org/copyleft/gpl.html
 */
package net.sourceforge.zmanim.Calendar;

import java.util.Calendar;
import java.util.Date;

import net.sourceforge.zmanim.util.GeoLocation;

/**
 * <p>
 * Description: A Java library for calculating zmanim.
 * </p>
 * The zmanim library is an API is a specialized calendar that can calculate
 * sunrise and sunset and Jewish <em>zmanim</em> (religious times) for prayers
 * and other Jewish religious duties. For a much more extensive list of zmanim
 * use the {@link ComplexZmanimCalendar} that extends this class. This class
 * contains the main functionality of the Zmanim library. See documentation for
 * the {@link ComplexZmanimCalendar} and {@link AstronomicalCalendar} for simple
 * examples on using the API.
 * <h2>Disclaimer:</h2>
 * While I did my best to get accurate results please do not rely on these
 * zmanim for <em>halacha lemaaseh</em>
 *
 * @author &copy; Eliyahu Hershfeld 2004 - 2009
 * @version 1.1
 */
public class ZmanimCalendar extends AstronomicalCalendar {
    private static final long serialVersionUID = 1;

    /**
     * The zenith of 16.1&deg; below geometric zenith (90&deg;). This
     * calculation is used for calculating <em>alos</em> (dawn) and
     * <em>tzais</em> (nightfall) in some opinions. This calculation is based
     * on the calculation that the time between dawn and sunrise (and sunset to
     * nightfall) is the time that is takes to walk 4 <em>mil</em> at 18
     * minutes a mil (<em>Ramba"m</em> and others). The sun's position at 72
     * minutes before {@link #getSunrise sunrise} in Jerusalem on the equinox is
     * 16.1&deg; below {@link #GEOMETRIC_ZENITH geometric zenith}.
     *
     * @see #getAlosHashachar()
     * @see ComplexZmanimCalendar#getAlos16Point1Degrees()
     * @see ComplexZmanimCalendar#getTzais16Point1Degrees()
     * @see ComplexZmanimCalendar#getSofZmanShmaMGA16Point1Degrees()
     * @see ComplexZmanimCalendar#getSofZmanTfilaMGA16Point1Degrees()
     * @see ComplexZmanimCalendar#getMinchaGedola16Point1Degrees()
     * @see ComplexZmanimCalendar#getMinchaKetana16Point1Degrees()
     * @see ComplexZmanimCalendar#getPlagHamincha16Point1Degrees()
     * @see ComplexZmanimCalendar#getPlagAlos16Point1ToTzaisGeonim7Point083Degrees()
     * @see ComplexZmanimCalendar#getSofZmanShmaAlos16Point1ToSunset()
     */
    protected static final double ZENITH_16_POINT_1 = GEOMETRIC_ZENITH + 16.1;

    /**
     * The zenith of 8.5&deg; below geometric zenith (90&deg;). This calculation
     * is used for calculating <em>alos</em> (dawn) and <em>tzais</em>
     * (nightfall) in some opinions. This calculation is based on the position
     * of the sun 36 minutes after {@link #getSunset sunset} in Jerusalem on
     * March 16, about 4 days before the equinox, the day that a solar hour is
     * one hour, which is 8.5&deg; below
     * {@link #GEOMETRIC_ZENITH geometric zenith}. The Ohr Meir considers this
     * the time that 3 small starts are visible, later than the required 3
     * medium stars.
     *
     * @see #getTzais()
     * @see ComplexZmanimCalendar#getTzaisGeonim8Point5Degrees()
     */
    protected static final double ZENITH_8_POINT_5 = GEOMETRIC_ZENITH + 8.5;

    // private AstronomicalCalculator astronomicalGeometryCalculator;

    private double candleLightingOffset = 18;

    /**
     * Returns <em>tzais</em> (nightfall) when the sun is 8.5&deg; below the
     * western geometric horizon (90&deg;) after {@link #getSunset sunset}. For
     * information on the source of this calculation see
     * {@link #ZENITH_8_POINT_5}.
     *
     * @return The <code>Date</code> of nightfall.
     * @see #ZENITH_8_POINT_5
     */
    public Date getTzais() {
        return this.getSunsetOffsetByDegrees(ZENITH_8_POINT_5);
    }

    /**
     * Returns <em>alos</em> (dawn) based on the time when the sun is
     * 16.1&deg; below the eastern {@link #GEOMETRIC_ZENITH geometric horizon}
     * before {@link #getSunrise sunrise}. For more information the source of
     * 16.1&deg; see {@link #ZENITH_16_POINT_1}.
     *
     * @return The <code>Date</code> of dawn.
     * @see ZmanimCalendar#ZENITH_16_POINT_1
     */
    public Date getAlosHashachar() {
        return getSunriseOffsetByDegrees(ZENITH_16_POINT_1);
    }

    /**
     * Method to return <em>alos</em> (dawn) calculated using 72 minutes
     * before {@link #getSeaLevelSunrise() sea level sunrise} (no adjustment for
     * elevation) based on the time to walk the distance of 4 <em>Mil</em> at
     * 18 minutes a <em>Mil</em>. This is based on the opinion of most
     * <em>Rishonim</em> who stated that the time of the <em>Neshef</em>
     * (time between dawn and sunrise) does not vary by the time of year or
     * location but purely depends on the time it takes to walk the distance of
     * 4 <em>Mil</em>.
     *
     * @return the <code>Date</code> representing the time.
     */
    public Date getAlos72() {
        return getTimeOffset(getSeaLevelSunrise(), -72 * MINUTE_MILLIS);
    }

    /**
     * This method returns <em>chatzos</em> (midday) following the opinion of
     * the GRA that the day for Jewish halachic times start at
     * {@link #getSunrise sunrise} and ends at {@link #getSunset sunset}. The
     * returned value is identical to {@link #getSunTransit()}
     *
     * @return the <code>Date</code> of chatzos.
     * @see AstronomicalCalendar#getSunTransit()
     */
    public Date getChatzos() {
        return getSunTransit();
    }

    /**
     * A method that returns "solar" midnight, or the time when the sun is at
     * it's <a href="http://en.wikipedia.org/wiki/Nadir">nadir</a>. <br/><br/><b>Note:</b>
     * this method is experimental and might be removed (or moved)
     *
     * @return the <code>Date</code> of Solar Midnight (chatzos layla).
     */
    public Date getSolarMidnight() {
        ZmanimCalendar clonedCal = (ZmanimCalendar) clone();
        clonedCal.getCalendar().add(Calendar.DAY_OF_MONTH, 1);
        Date sunset = getSunset();
        Date sunrise = clonedCal.getSunrise();
        return getTimeOffset(sunset, getTemporalHour(sunset, sunrise) * 6);
    }

    // public Date getChatzosLaylaRSZ() {
    // ZmanimCalendar clonedCal = (ZmanimCalendar)clone();
    // clonedCal.getCalendar().add(Calendar.DAY_OF_MONTH, 1);
    // Date sunset = getSunset();
    // Date sunrise = clonedCal.getAlosHashachar();
    // return getTimeOffset(sunset, getTemporalHour(sunset, sunrise) * 6);
    // }

    /**
     * This method returns the latest <em>zman krias shema</em> (time to say
     * Shema in the morning). This time is 3
     * <em>{@link #getShaahZmanisGra() shaos zmaniyos}</em> (solar hours)
     * after {@link #getSunrise() sunrise} based on the opinion of the
     * <em>GR"A</em> and the <em>Baal Hatanya</em> that the day is
     * calculated from sunrise to sunset. This returns the time 3 *{@link #getShaahZmanisGra()}
     * after {@link #getSunrise() sunrise}.
     *
     * @return the <code>Date</code> of the latest zman shema.
     * @see ZmanimCalendar#getShaahZmanisGra()
     */
    public Date getSofZmanShmaGRA() {
        return getTimeOffset(getSunrise(), getShaahZmanisGra() * 3);
    }

    /**
     * This method returns the latest <em>zman krias shema</em> (time to say
     * Shema in the morning) in the opinion of the <em>MG"A</em> based on
     * <em>alos</em> being 72 minutes before {@link #getSunrise() sunrise}.
     * This time is 3 <em> shaos zmaniyos</em> (solar hours) after dawn based
     * on the opinion of the <em>MG"A</em> that the day is calculated from a
     * dawn of 72 minutes before sunrise to nightfall of 72 minutes after
     * sunset. This returns the time of 3 * <em>shaos zmaniyos</em> after
     * dawn.
     *
     * @return the <code>Date</code> of the latest zman shema.
     * @see ComplexZmanimCalendar#getShaahZmanis72Minutes()
     * @see ComplexZmanimCalendar#getAlos72()
     * @see ComplexZmanimCalendar#getSofZmanShmaMGA72Minutes()
     */
    public Date getSofZmanShmaMGA() {
        return getTimeOffset(getAlos72(), getShaahZmanisMGA() * 3);
    }

    /**
     * This method returns the <em>tzais</em> (nightfall) based on the opinion
     * of the <em>Ramba"m</em> and <em>Rabainu Tam</em> that <em>tzais</em>
     * is calculated as the time it takes to walk 4 <em>Mil</em> at 18 minutes
     * a <em>Mil</em> for a total of 72 minutes. Even for locations above sea
     * level, this is calculated at sea level, since the darkness level is not
     * affected by elevation.
     *
     * @return the <code>Date</code> representing 72 minutes after sea level
     *         sunset.
     */
    public Date getTzais72() {
        return getTimeOffset(getSeaLevelSunset(), 72 * MINUTE_MILLIS);
    }

    /**
     * A method to return candle lighting time. This is calculated as
     * {@link #getCandleLightingOffset()} minutes before sunset. This will
     * return the time for any day of the week, since it can be used to
     * calculate candle lighting time for <em>yom tov</em> (holidays) as well.
     *
     * @return candle lighting time.
     * @see #getCandleLightingOffset()
     * @see #setCandleLightingOffset(double)
     */
    public Date getCandelLighting() {
        return getTimeOffset(getSunset(), -getCandleLightingOffset()
                * MINUTE_MILLIS);
    }

    /**
     * This method returns the latest
     * <em>zman tefilah<em> (time to pray morning prayers). This time is 4
     * hours into the day based on the opinion of the <em>GR"A</em> and the </em>Baal Hatanya</em>
     * that the day is calculated from sunrise to sunset. This returns the time
     * 4 * {@link #getShaahZmanisGra()} after {@link #getSunrise() sunrise}.
     *
     * @return the <code>Date</code> of the latest zman tefilah.
     * @see ZmanimCalendar#getShaahZmanisGra()
     */
    public Date getSofZmanTfilaGRA() {
        return getTimeOffset(getSunrise(), getShaahZmanisGra() * 4);
    }

    /**
     * This method returns the latest <em>zman tfila</em> (time to say the
     * morning prayers) in the opinion of the <em>MG"A</em> based on
     * <em>alos</em> being {@link #getAlos72() 72} minutes before
     * {@link #getSunrise() sunrise}. This time is 4
     * <em>{@link #getShaahZmanisMGA() shaos zmaniyos}</em> (temporal hours)
     * after {@link #getAlos72() dawn} based on the opinion of the <em>MG"A</em>
     * that the day is calculated from a {@link #getAlos72() dawn} of 72 minutes
     * before sunrise to {@link #getTzais72() nightfall} of 72 minutes after
     * sunset. This returns the time of 4 * {@link #getShaahZmanisMGA()} after
     * {@link #getAlos72() dawn}.
     *
     * @return the <code>Date</code> of the latest zman tfila.
     * @see #getShaahZmanisMGA()
     * @see #getAlos72()
     */
    public Date getSofZmanTfilaMGA() {
        return getTimeOffset(getAlos72(), getShaahZmanisMGA() * 4);
    }

    /**
     * This method returns the time of <em>mincha gedola</em>.<em>Mincha gedola</em>
     * is the earliest time one can pray mincha. The Ramba"m is of the opinion
     * that it is better to delay <em>mincha</em> until
     * <em>{@link #getMinchaKetana() mincha ketana}</em> while the <em>Ra"sh,
     * Tur, GR"A</em>
     * and others are of the opinion that <em>mincha</em> can be prayed
     * <em>lechatchila</em> starting at <em>mincha gedola</em>. This is
     * calculated as 6.5 {@link #getTemporalHour() solar hours} after sunrise.
     * This calculation is calculated based on the opinion of the <em>GR"A</em>
     * and the <em>Baal Hatanya</em> that the day is calculated from sunrise
     * to sunset. This returns the time 6.5 *{@link #getShaahZmanisGra()} after
     * {@link #getSunrise() sunrise}.
     *
     * @return the <code>Date</code> of the time of mincha gedola.
     * @see #getShaahZmanisGra()
     * @see #getMinchaKetana()
     */
    public Date getMinchaGedola() {
        return getTimeOffset(getSunrise(), getShaahZmanisGra() * 6.5);
    }

    /**
     * This method returns the time of <em>mincha ketana</em>. This is the
     * perfered earliest time to pray <em>mincha</em> in the opinion of the
     * Ramba"m and others. For more information on this see the documentation on
     * <em>{@link #getMinchaGedola() mincha gedola}</em>. This is calculated
     * as 9.5 {@link #getTemporalHour() solar hours}after sunrise. This
     * calculation is calculated based on the opinion of the <em>GR"A</em> and
     * the <em>Baal Hatanya</em> that the day is calculated from sunrise to
     * sunset. This returns the time 9.5 * {@link #getShaahZmanisGra()} after
     * {@link #getSunrise() sunrise}.
     *
     * @return the <code>Date</code> of the time of mincha gedola.
     * @see #getShaahZmanisGra()
     * @see #getMinchaGedola()
     */
    public Date getMinchaKetana() {
        return getTimeOffset(getSunrise(), getShaahZmanisGra() * 9.5);
    }

    /**
     * This method returns he time of <em>plag hamincha</em>. This is
     * calculated as 10.75 hours after sunrise. This calculation is calculated
     * based on the opinion of the <em>GR"A</em> and the <em>Baal Hatanya</em>
     * that the day is calculated from sunrise to sunset. This returns the time
     * 10.75 *{@link #getShaahZmanisGra()} after {@link #getSunrise() sunrise}.
     *
     * @return the <code>Date</code> of the time of <em>plag hamincha</em>.
     */
    public Date getPlagHamincha() {
        return getTimeOffset(getSunrise(), getShaahZmanisGra() * 10.75);
    }

    /**
     * Method to return a <em>shaah zmanis</em> ({@link #getTemporalHour temporal hour})
     * according to the opinion of the <em>GR"A</em> and the
     * <em>Baal Hatanya</em>. This calculation divides the day based on the
     * opinion of the <em>GR"A</em> and the <em>Baal Hatanya</em> that the
     * day runs from {@link #getSunrise() sunrise} to {@link #getSunset sunset}.
     * The day is split into 12 equal parts each part with each one being a
     * <em>shaah zmanis</em>. This method is identical to
     * {@link #getTemporalHour} (it is actually a wrapper that calls that
     * method) and is provided for clarity.
     *
     * @return the <code>long</code> millisecond length of a
     *         <em>shaah zmanis</em>.
     * @see #getTemporalHour()
     */
    public long getShaahZmanisGra() {
        return getTemporalHour();
    }

    /**
     * Method to return a <em>shaah zmanis</em> (temporal hour) according to
     * the opinion of the MGA. This calculation divides the day based on the
     * opinion of the <em>MGA</em> that the day runs from dawn to dusk (for
     * sof zman krias shema and tfila). Dawn for this calculation is 72 minutes
     * before sunrise and dusk is 72 minutes after sunset. This day is split
     * into 12 equal parts with each part being a <em>shaah zmanis</em>.
     * Alternate mothods of calculating a <em>shaah zmanis</em> are available
     * in the subclass {@link ComplexZmanimCalendar}.
     *
     * @return the <code>long</code> millisecond length of a
     *         <em>shaah zmanis</em>.
     */
    public long getShaahZmanisMGA() {
        return getTemporalHour(getAlos72(), getTzais72());
    }

    /**
     * Default constructor will set a default {@link GeoLocation#GeoLocation()},
     * a default
     * {@link net.sourceforge.zmanim.Calculator.AstronomicalCalculator#getDefault() AstronomicalCalculator} and
     * default the calendar to the current date.
     *
     * @see AstronomicalCalendar#AstronomicalCalendar()
     */
    public ZmanimCalendar() {
        super();
    }

    /**
     * A constructor that takes a {@link GeoLocation} as a parameter.
     *
     * @param location the location
     */
    public ZmanimCalendar(GeoLocation location) {
        super(location);
    }

    /**
     * @see java.lang.Object#equals(Object)
     */
    public boolean equals(Object object) {
        if (this == object) {
            return true;
        }
        if (!(object instanceof ZmanimCalendar)) {
            return false;
        }
        ZmanimCalendar zCal = (ZmanimCalendar) object;
        // return getCalendar().getTime().equals(zCal.getCalendar().getTime())
        return getCalendar().equals(zCal.getCalendar())
                && getGeoLocation().equals(zCal.getGeoLocation())
                && getCalculator().equals(
                zCal.getCalculator());
    }

    /**
     * @see java.lang.Object#hashCode()
     */
    public int hashCode() {
        int result = 17;
        // needed or this and subclasses will return identical hash
        result = 37 * result + getClass().hashCode();
        result += 37 * result + getCalendar().hashCode();
        result += 37 * result + getGeoLocation().hashCode();
        result += 37 * result + getCalculator().hashCode();
        return result;
    }

    /**
     * A method to get the offset in minutes before
     * {@link AstronomicalCalendar#getSunset() sunset} that is used in
     * calculating candle lighting time. The default time used is 18 minutes
     * before sunset. Some calendars use 15 minutes, while the custom in
     * Jerusalem is to use a 40 minute offset. Please check the local custom for
     * candel lighting time.
     *
     * @return Returns the candle lighting offset to set in minutes..
     * @see #getCandelLighting()
     */
	public double getCandleLightingOffset() {
		return candleLightingOffset;
	}

	/**
     * A method to set the offset in minutes before
     * {@link AstronomicalCalendar#getSunset() sunset} that is used in
     * calculating candle lighting time. The default time used is 18 minutes
     * before sunset. Some calendars use 15 minutes, while the custom in
     * Jerusalem is to use a 40 minute offset.
     *
     * @param candleLightingOffset The candle lighting offset to set in minutes.
     * @see #getCandelLighting()
     */
	public void setCandleLightingOffset(double candleLightingOffset) {
		this.candleLightingOffset = candleLightingOffset;
	}
}
